A federal grand jury has indicted a 26-year-old American on terror charges relating to an alleged plot to strike the nation's capital with several explosive-laden, remote-controlled airplanes.

Rezwan Ferdaus, a U.S. citizen from Ashland, Mass., and Northeastern University physics graduate, was nabbed in an elaborate FBI sting after he told undercover officers exactly how he planned to arm "small drone airplanes" with explosives in order to hit the Pentagon and U.S. Capitol building before opening fire on the survivors, federal officials said in a statement.

Ferdaus was indicted on six counts, including "attempting to damage and destroy a federal building by means of an explosive" and "attempting to provide material support to terrorists."

An attorney for Ferdaus has not returned requests for comments on the charges against him.

According to the indictment, Ferdaus believed his attack could "decapitate" the U.S. "military center".

Feds: Ferdaus Said Women, Children Were 'Enemies of Allah'

Federal officials said Ferdaus appeared to have been radicalized online by Islamist videos and writings. By 2010, Ferdaus believed he was working for al Qaeda when he began modifying cell phones to serve as electrical switches for improvised explosive devices (IEDs) to be passed on to fighters in the Middle East.

"During a June 2011 meeting, he appeared gratified when he was told that his first phone detonation device had killed three U.S. soldiers and injured four or five others in Iraq. Ferdaus responded, 'That was exactly what I wanted,'" the Department of Justice said in a statement after Ferdaus' arrest Wednesday.

The cell phones, however, never got anywhere near the Middle East as Ferdaus was actually handing them over to undercover officers for the FBI. Still, Ferdaus appeared to want to do more, investigators said.

"Ferdaus envisioned causing a large 'psychological' impact by killing Americans, including women and children, who he referred to as 'enemies of Allah,'" the DOJ's statement said. "According to the affidavit, Ferdaus' desire to attack the United States is so strong that he confided, 'I just can't stop; there is no other choice for me.'"

Ferdaus allegedly wanted to command a team of six operatives that would use up to three remote-controlled aircraft filled with explosives in the "aerial" part of the attack before firing on any survivors in a follow-up "ground" attack.

Federal investigators said Ferdaus traveled to Washington, D.C., to "conduct surveillance" and take photographs of his targets before acquiring his weapons, including six AK-47 assault rifles, grenades and what he believed to be C-4 explosives.

"Although Ferdaus was presented with multiple opportunities to back out of his plan, including being told that his attack would likely kill women and children, the affidavit alleges that Ferdaus never wavered in his desire to carry out the attacks," the DOJ said.